Mr Garner resigned as vice-president of the state Senate when the Klan took violent exception to his support for moves to remove the Confederate battle emblem from the state flag. Mr Garner, a 45-year-old Democrat, had argued that the emblem was a constant reminder of civil war and the South's support for slavery.
"The Klan was furious with forward-looking politicians like Mr Garner and they let their fury be known in no uncertain terms," said Christopher Hamilton, legal adviser to the Georgia Board of Pardons and Paroles, of which Mr Garner is chairman.
"They threatened to kill him, a threat which he ignored. He tried to carry on as normal, even though his home had to be surrounded by state troopers for his protection. But then they said they would kill his three children. He decided to resign rather than put them at risk."
To avoid losing Mr Garner from public life, the state Governor, Zell Miller, appointed him to the full-time job of chairing the Pardons and Paroles Board. "He is a very reflective and humane man," said Mr Hamilton. "He has been deeply affected by this case."
For more than 12 hours, between Wednesday night and yesterday morning, it seemed that Mr Garner's humane side might have shone through. He took the unprecedented step of visiting Ingram in prison, saying he wanted to "look him in the eye" before deciding whether he should live or die.
The men met at about 7pm in Ingram's cell at the Georgia Diagnostic and Classification Center in Jackson and they talked for almost half an hour. Sources within the board's administration said the meeting came about for two reasons. First, the chairman wanted to know why, during 12 years on death row, Ingram had never written to the board expressing remorse, arguing a case or simply pleading for clemency. Almost all other death row prisoners have done so.
Second, Mr Garner had just returned from a 10-day holiday in London and Hereford. "He was right in the middle of the debate over there and he got unusually close to public opinion," said one insider. "That had a very profound effect on him and he wanted to meet Ingram for himself."
Despite the pleading of Ingram's mother, Ann, and barrister David Marshall, of the Bar Council's human rights committee, at a meeting in Atlanta on Wednesday, members of the board were not swayed.
James Morris, a former police and probation officer, Garfield Hammonds Jr, a former Drug Enforcement Agency officer, Timothy Jones, a former parole officer who won a Purple Heart in Vietnam, and Bobby Whitworth, a former Commissioner of Corrections, voted unanimously for the sentence to be carried out.
Since the death penalty was restored in Georgia in 1973, only six of the 24 pleas for clemency have been granted by the board. Its members have a reputation for making difficult decisions.
"They're appointed by the Governor and he wouldn't appoint them unless he thought they had the courage to carry out the death sentence," said Mr Hamilton.
The board was established in 1943 when the Governor of the day, Eugene Talmadge, was found to be taking bribes to accept pleas for clemency. In other American states, the Governor still has the power to issue stays of execution.